ft_container/includes/iterator.hpp

#pragma once
#include <cstddef>
#include <iterator> // only for std/ft tags compatibility

namespace ft {

template < class Iterator > struct iterator_traits {
  typedef typename Iterator::iterator_category iterator_category;
  typedef typename Iterator::value_type        value_type;
  typedef typename Iterator::difference_type   difference_type;
  typedef typename Iterator::pointer           pointer;
  typedef typename Iterator::reference         reference;
};

template < class T > struct iterator_traits< T * > {
  typedef std::random_access_iterator_tag iterator_category;
  typedef T                               value_type;
  typedef ptrdiff_t                       difference_type;
  typedef T                              *pointer;
  typedef T                              &reference;
};

template < class T > struct iterator_traits< const T * > {
  typedef std::random_access_iterator_tag iterator_category;
  typedef T                               value_type;
  typedef ptrdiff_t                       difference_type;
  typedef T                              *pointer;
  typedef T                              &reference;
};

// Iterator classes:
template < class Category, class T, class Distance = ptrdiff_t,
           class Pointer = T *, class Reference = T & >
struct iterator {
  typedef Category  iterator_category;
  typedef T         value_type;
  typedef Distance  difference_type;
  typedef Pointer   pointer;
  typedef Reference reference;
};

template < class T >
class random_access_iterator
    : public iterator< std::random_access_iterator_tag, T > {

public:
  typedef
      typename iterator< std::random_access_iterator_tag, T >::iterator_category
          iterator_category;
  typedef typename iterator< std::random_access_iterator_tag, T >::value_type
      value_type;
  typedef
      typename iterator< std::random_access_iterator_tag, T >::difference_type
             difference_type;
  typedef T *pointer;
  typedef T &reference;

private:
  pointer _ptr;

public:
  random_access_iterator(pointer ptr = NULL) : _ptr(ptr) {}

  random_access_iterator(const random_access_iterator &other)
      : _ptr(other._ptr) {}

  random_access_iterator &operator=(const random_access_iterator &other) {
    _ptr = other._ptr;
    return *this;
  }

  pointer base(void) const { return _ptr; }

  reference operator*(void) const { return *_ptr; }

  random_access_iterator operator+(const difference_type n) const {
    return (random_access_iterator(_ptr + n));
  }

  difference_type operator+(const random_access_iterator &rhs) const {
    return _ptr + rhs._ptr;
  }

  friend random_access_iterator operator+(const difference_type   n,
                                          random_access_iterator &rhs) {
    return random_access_iterator(rhs._ptr + n);
  }

  random_access_iterator &operator++() {
    ++_ptr;
    return *this;
  }

  random_access_iterator operator++(int) {
    random_access_iterator ret(*this);
    ++(*this);
    return ret;
  }

  random_access_iterator &operator+=(const difference_type n) {
    _ptr += n;
    return *this;
  }

  random_access_iterator operator-(const difference_type n) const {
    return (random_access_iterator(_ptr - n));
  }

  friend random_access_iterator operator-(const difference_type   n,
                                          random_access_iterator &rhs) {
    return random_access_iterator(rhs._ptr - n);
  }

  random_access_iterator &operator--() {
    --_ptr;
    return *this;
  }

  random_access_iterator operator--(int) {
    random_access_iterator ret(*this);
    --(*this);
    return ret;
  }
  random_access_iterator &operator-=(const difference_type n) {
    _ptr -= n;
    return *this;
  }

  pointer operator->(void) { return _ptr; }

  reference operator[](const difference_type n) { return *(_ptr + n); }

  friend bool operator==(const random_access_iterator &lhs,
                         const random_access_iterator &rhs) {
    return lhs._ptr == rhs._ptr;
  }

  friend bool operator!=(const random_access_iterator &lhs,
                         const random_access_iterator &rhs) {
    return lhs._ptr != rhs._ptr;
  }

  friend bool operator<(const random_access_iterator &lhs,
                        const random_access_iterator &rhs) {
    return lhs._ptr < rhs._ptr;
  }

  friend bool operator<=(const random_access_iterator &lhs,
                         const random_access_iterator &rhs) {
    return lhs._ptr <= rhs._ptr;
  }

  friend bool operator>(const random_access_iterator &lhs,
                        const random_access_iterator &rhs) {
    return lhs._ptr > rhs._ptr;
  }

  friend bool operator>=(const random_access_iterator &lhs,
                         const random_access_iterator &rhs) {
    return lhs._ptr >= rhs._ptr;
  }

  operator random_access_iterator< const T >() const {
    return random_access_iterator< const T >(_ptr);
  }
};

template < class It > std::size_t distance(It first, It last) {
  size_t ret = 0;
  while (first != last && ++ret)
    first++;
  return ret;
}

template < class It1, class It2 >
bool equal(It1 first1, It1 last1, It2 first2) {
  while (first1 != last1) {
    if (!(*first1 == *first2))
      return false;
    ++first1;
    ++first2;
  }
  return true;
}

template < class It1, class It2, class BinaryPredicate >
bool equal(It1 first1, It1 last1, It2 first2, BinaryPredicate pred) {
  while (first1 != last1) {
    if (!pred(*first1, *first2))
      return false;
    ++first1;
    ++first2;
  }
  return true;
}

template < class It1, class It2 >
bool lexicographical_compare(It1 first1, It1 last1, It2 first2, It2 last2) {
  while (first1 != last1) {
    if (first2 == last2 || *first2 < *first1)
      return false;
    else if (*first1 < *first2)
      return true;
    ++first1;
    ++first2;
  }
  return (first2 != last2);
}

template < class It1, class It2, class Compare >
bool lexicographical_compare(It1 first1, It1 last1, It2 first2, It2 last2,
                             Compare comp) {
  while (first1 != last1) {
    if (first2 == last2 || comp(*first2, *first1))
      return false;
    else if (comp(*first1, *first2))
      return true;
    ++first1;
    ++first2;
  }
  return (first2 != last2);
}

template < class T1, class T2 >
typename random_access_iterator< T1 >::difference_type
operator-(const random_access_iterator< T1 > &lhs,
          const random_access_iterator< T2 > &rhs) {
  return lhs.base() - rhs.base();
}

} // namespace ft